Cyanine dyestuffs



Patented Mar. 5, 1946 CYANINE DYE STUFFS John David Kendall and Douglas James Fry, Iln ford, England, assignors to Ilford Limited, ll-

ford, England, a British company No Drawing. Application March 5, 1941, Serial No. 381,926. In Great Britain April 19, 1940 8 Claims.

This invention relates to the production of dye stufis and particularly to the production of dyestufis capable of optically sensitising silver halide photographic emulsions and of dyeing textile materials.

In our application No. 381,925, filed on even date herewith, there is described a process for preparing dyestuffs and dyestuff intermediates which comprises condensing together two molecules of a heterocyclic keto methylene compound of the general formula:

where R1 is a hydrogen atom or hydrocarbon group and X is an oxygen or sulphur atom, in the presence of an anhydride of a monocarboxylic acid or an ortho ester of a monocarboxylic acid, and in the presence of a strong base, i. e., a base stronger than ammonia.

The products of this process have the general and thus contain two thione groupings each in the on position to a heterocyclic nitrogen atom- (Ra in this formula is a hydrogen atom or hydrocarbon group).

In our application No. 186,251, filed January 2, 1938, we have described a process in which photographic sensitising dyestuiTs are producedby condensing certain types of compounds containing a rhodanic acid nucleus with an alkyl salt to convert the thione grouping of the rhodanic acid nucleus into a reactive roup, and condensing the resulting compound with one of seven types of compounds which are set forth in the specification.

It has now been discovered that the above compounds of Formula II which contain two rhodanic acid nuclei may be condensed with alkyl and aralkyl salts and with the seven types of compound set forth in application No. 186,251 to produce photographic sensitising dyestufis.

According to the present invention, therefore, dyestuffs are produced by reacting a compound of the general Formula II with an alkyl or aralkyl salt to convert the thione grouping into a reactive group and condensing the resulting compound with one of the'following types of compounds.

(a) A fi e ered ring cam-pound containing the system:

(b) A quaternary salt of a heterocyclic nitrogen compound havinga reactive methyl group or external methylene group or N-reactive amino or imino group in the a or 7 position to a heterocycl c nitrogen atom n (c') A compound containingthe grouping:

onto .3; Gigs on;

where R1, R2 and 33 m y e alkyl a y r, ra-lkyl group o B1 and at may b pa of t a arylen ring. n

d) qa bce el e c mp n s c tain ng avk methy ne gr up (e) Acids or e er .ot he t p where X is hydrogen or a mDno-valent substituent, R is hydrogen or an alkyl or similar group andnis0or1 ,(f) Anhydrides of acids of the general formula:

CHa XI 2.n1=C OQ where isihyd oeen or a :monovalent grou in antic-151012? i fi Ammonia orxam d nes or hydrazines or diamines or their salts. 1 i r 7 u T e fore o ng commends. .(a) to (y) are cha aete is d by the fa t that t y all contain a mac: five CHz;g-roup-.orareaetiv .NH groupr Ac din to a further i ature .oi th invent en. 1

hen t e zfi e-m mzbered r comp unds eon-v te n ng he system taco-a,

45 whi h are condensed with the quaternary t of the compounds of Formula II correspond to the enera-1 formula: v

(Stei s a hyd ogen atom or a hydrocarbon (R. being a hydrogen atom or a hydrocarbon group.) The product will once more'contain thione groupings, and by proceeding in this way the condensation may be repeated as often as desired; the final product obtained by any such series of condensations may be further condensed according to the invention with any of the other types of compound (12) to (9) above to give a dyestufi comprising two nuclear groups, for example, heterocyclic nitrogen nuclei, linked by a chain of any desired number of keto-thiazoline or keto-oxazoline rings, which chain may also include other rings such as cyclopentadiene rings or methine groups or nitrogen atoms according to the condensation carried out.

It is believed that in the first part of the process the thione group is converted into a reactive thioether grouping which may then react with any of the other groupings (a) to (g) "The condensation may be carried out by first carrying out the reaction with the alkyl or aralkyl salt and then reacting the resulting compound with the other compounds (a) to (g) or in the case where quaternary salts of heterocyclic nuclei are employed, the two heterocyclic bases may be fused together with the alkyl salt and the reaction completed by heating in the presence of an acid binding substance, for example, pyridine, as described in British Patent No. 438,420. i 7

Examples of the compounds of type (a) which may be condensed with the compounds" of Formula II according to our invention are those enumerated in the specification of British Patent No. 426,718, filed October 3,1933, namely, oxindoles, pyrazole--ones, hydantoin, thiohydantoin, b-hydantoin, \p-thio-hydantoin.

Compounds of type (b) which may be employed may be any of those which have been used or proposed for use in the many processes for the production of cyanine and similar dyemembered ring compound containing the sysstufis, for example, thiazoles, oxazoles, selenazoles and their polycyclic homologues such as those of the benzene, naphthalene, acenaphthene and anthracene series; pyridine and its polycyclic homologues such as quinoline and a and p naphthaquinolines; lepidines; indolenines; diazines; such as pyrimidines and quinazolines; diazoles (e. g., thio-ppdiazole) oxazolines, thiazolines and selenazolines.

acid. A. compound of type if) 'is 'crotonic-an hydride, whilst'compounds of'type (g) aream- The polycyclic compounds of these series may also be substituted monium salts such as ammonium nitrate, hydrazines and substituted hydrazines.

The dyestufis produced in accordance with the present invention are sensitisers for photographic silver halide emulsions and the invention also includes photographic silver halide emulsions sensitised with the dyestufis produced in accordance with the present invention.

The invention is illustrated by the following specific examples: 0

Example 1 A dyestuff was prepared by the following method: 0.80 gm. of (2-thio-3-methy1-4-ketotetrahydrothiazolyl 5) -(2'-thio-3'methyl-4- keto tetrahydrothiazolylidene-5') -mesomethyl methane, 1.49 gms. of l-methylbenzthiazole and 5 gms. of ethyl-p-toluene sulphonate. were mixed together and fused for 2 hours at 160? .C. 10 ccs. of pyridine were added and the mixture warmed on a water bath and gently refluxed for 25 minutes. The mixture was then poured into a beaker, and cooled. The product crystallised out and on recrystallisation from methyl alcohol, had a melting point of 280 C. with decomposition. Its probable formula is:

This dyestufi, incorporated in a silver iodobromide emulsion, extends the sensitivity to about 6600 A.

Example 2 A dyestufi was prepared by a method analogous to that of Example 1 employing 4.5 gms. of'methyl-p-toluene sulphonate instead of ethyl-p-toluene sulphonate. Theproduct on recrystallisation had a melting point of 280 C. with decomposition. Its' probable formula is:

A dyestufi was prepared by the following method: 0.85 gm. of (2-thio-3-ethy1-4-keto-tetrahydrothiazolyl-fi) -(2-thio-3'-ethyl-4 keto tetrahydrothiazolylidene-E') -meso' methyl methane, 1.49 gms. of I-methylbenzthiazole and 5 gms. of ethyl-p-toluene sulphonate were fused for A hour at C. 10 ccs. of pyridine were then addedand the mixture refluxed for 10 minutes. The mixture was then poured into a beaker and allowed to cool. It was diluted with water and a solutionoffpotassium' iodide was added, The product on recrystallisation from methyl alcohol had a melting point of 275 C. with decomposition. Its probable formula is: v p

This dyestuff",v incorporated in a silver iodobromide emulsion, extends the sensitivity toabout Example 4 A dyestuff was prepared by the following method: 0.80 gm. of ('2-thio-3-methyl'-4-keto-tetrahydrothiazolyl-)-(2'-thio-3-methyl-4"-keto tetv product was then boiled out with benzene, and then with methyl alcohol. It had a melting; point.

of 271 C. with decomposition. Its probable formula is: V

Example 5 A d'yestufi was prepared by the following method: 0.80 gm. of (2-thio-3-methyl-4-ketdtetrahydrothiazolyl-5) (2' -thio 3' methyl 4 keto-tetrahydrothiazolylidenee5'?) meso methyl methane, 1.33 gms. of l-methylbenzoxazole and 4.0 gms. of methyl-p-toluene sulphonate were mixed together andifused for 1 /2 hours at 150 C. cos. of pyridine were then added, and the mixture refluxed for half an hour. The mixture was cooled and solid matter separated which was removed by filtration. It was boiled out with 100 cos. of methyl alcohol. The crystalline product had a melting point of 292 C. with decomposition. Its probable formula is:

As already indicated, the dyestufis of this in- 50 vention are of especial value as sensitisers for gelatino-silver-halide photographic emulsions, e. g. silver chloride, silver bromide, silver chlorobromide and silver iodobromide emulsions. Hownaphthenijc acids, sulphonat'ed. naphthalene formaldehyde condensation products, sulphonated long. chain fatty alcohols and. similar agents.

5 The following are. exarr-iples;of: the useofthe dyestuffs in this. connection (the parts: referred to are parts byv weight).

Example 6 10 3 parts ofthe: dyestuff of Example were ground to a paste with a little water and then added to. a solution of 100 parts of. Tergitol" The volume of the solution was then adjusted to 3,300 parts by the addition of further water. 110 parts of; cellulose acetate fabric were immersed in the dye-bath thus formed and the bath was heated for SQminutes at 80 C. The fabric was then removed, washed and dried. It .was dyed a delicate shade, oflavender.

. 20 Example 7.

The procedure indicated in Example 6 was followed using 3- parts of the dyestutf of Example 2 and 30 parts of Perminal W, making the total bulk to 3,060 parts and dyeing, by means of this bath, 1202'- parts of cellulose acetate fabric. The fabric" was dyed a pale steel-blue shade.

What we claim is:

1'. Process for the manufacture of dyestuffs which comprises condensing a compound of the general formula:

la. 4.. where R1. and R2 are selected from the group consisting of hydrogen atoms and hydrocarbon 40 groups, with a salt selectedfrom the group consisting of alkyl and aralkyl salts and condensing the resulting compound with a quaternary salt of a heterocyclic nitrogen compound having, in a position selected from the a and 7 positions to the quaternary nitrogen atom, a reactive methylene group.

2. Process for the manufacture of dyestuffs which comprises condensing a compound of the general formula:

ever, they are also of value as textile dyestufis, 1'1, l t;

where R1 is selected from the group consisting of a hydrogen atom and a hydrocarbon group,

and R is a hydrocarbon radical, with a quaterv nizing salt selected from the group consisting of alkyl and aralkyl salts and condensing the resulting compound with a quaternary salt of a heterocyclic nitrogen compound having,-in a position selected from the alpha and gamma positions to the quaternary nitrogen atom, a reactive methylene group. 3. A dyestufi of the general formula:

necessary to complete a heterocyclic nucleus of where X is an atom selected from the:g'roup.conwhich in the form of' Crystals melts at 280) C. sistirig .of themxygen' atom and thefsulphur witli' decom'position. Y atom,';Ri and R2" are selectedfiroml'th group 7. A dyestufi having the formula:

consisting of hydrogen atoms and hydrocarbon any. 7

nimll V S., 5. groups, isas a positive integer R3 is selected a 343:6 CH S fromjhe group consisting of alkyl and aralkyl .l groups, A is an acid residue and D is the residue v ZH= /C=CHC of a heterocyclic nucleus .of the type usual in N :0 cyanine dyes. r N

. l v .i ,H V 0,5 4. Textile material dyed with a dyestufi as 10 f 5 V 0&8; claimed in-claim 3. I whichrinthe form'ofrl'crystals melts at 275 C. 5. A dyestufi of the general formula: with decomposition; i

r I I 111- whefe x is an atom selected from the group 3. Adyestufi having t formula; consisting of oxygen and sulfur, R1 is selected CH3 from; the group consisting of a hydrogen atom 25 0 I g 0 and ahydrocarbon group, R is a hydrocarbon \j (V/ radical, R3 is a hydrocarbongroup selected from -cH= C=CH the group consisting of alkyl; and aralkyl groups, n i small positive integer, A is the negative 1' N j v N radical of an acid, and D constitutes the atoms 39 j oi c1n1so X CH8 g \mmsoa the type contained in cyanine dyes. I

M11535 in? m 9 cry tals inelts at 292 c. A having the W r seewers; a .7 

